English
Related papers

Related papers: The Dark Neutral Medium is (Mostly) Molecular Hydr…

200 papers

We present results of a blind search for Galactic HI 21-cm absorption lines toward 19130 radio sources, using 390 pointings of MALS, each pointing centered on a source brighter than 200 mJy. We detected 3640 HI absorption features. This…

We present the first detection of HCO$^+$ absorption in the Magellanic System. Using the Australia Telescope Compact Array (ATCA), we observed 9 extragalactic radio continuum sources behind the Magellanic System and detected HCO$^+$…

There are relatively few H2CO mappings of large-area giant molecular cloud (GMCs). H2CO absorption lines are good tracers for low-temperature molecular clouds towards star formation regions. Thus, the aim of the study was to identify H2CO…

Astrophysics of Galaxies · Physics 2011-08-22 Chuan Peng Zhang , Jarken Esimbek , Jian Jun Zhou , Gang Wu , Zhi Mao Du

CO$_2$ is an important, stable, and abundant molecule in the Universe, but it is very difficult to detect because it has no observable pure rotational transitions. The unique sensitivity and resolution of the James Webb Space Telescope…

Astrophysics of Galaxies · Physics 2026-02-25 J. Qiu , A. Ciurlo , M. R. Morris , P. Vermot , J. L. Bourlot , D. Rouan , A. Togi , T. Do , A. M. Ghez , E. Bron , F. L. Petit , Y. Clénet , E. A. C. Mills , J. R. Lu

A growing body of evidence has been supporting the existence of so-called "dark molecular gas" (DMG), which is invisible in the most common tracer of molecular gas, i.e., CO rotational emission. DMG is believed to be the main gas component…

Astrophysics of Galaxies · Physics 2015-03-10 Di Li , Duo Xu , Carl Heiles , Zhichen Pan , Ningyu Tang

We present the first results on the diffuse transition clouds observed in [CII] line emission at 158 microns (1.9 THz) towards Galactic longitudes near 340deg (5 LOSs) and 20deg (11 LOSs) as part of the GOT C+ survey. Out of the total 146…

Astrophysics of Galaxies · Physics 2015-05-19 T. Velusamy , W. D. Langer , J. L. Pineda , P. F. Goldsmith , D. Li. , H. W. Yorke

We have used the BIMA array to image the Galactic Center with a 19-pointing mosaic in HCN(1-0), HCO+(1-0), and H 42-alpha emission with 5 km/s velocity resolution and 13'' x 4'' angular resolution. The 5' field includes the circumnuclear…

We present Giant Metrewave Radio Telescope (GMRT) observations of OH absorption in B3~1504+377 ($z \sim 0.673$) and PKS 1413+135 ($z \sim 0.247$). OH has now been detected in absorption towards four intermediate redshift systems, viz. the…

Astrophysics · Physics 2009-11-07 Nissim Kanekar , Jayaram N Chengalur

Carbon monoxide (CO) is a poor tracer of H$_{2}$ in the diffuse interstellar medium (ISM), where most of the carbon is not incorporated into CO molecules unlike the situation at higher extinctions. We present a novel, indirect method to…

Astrophysics of Galaxies · Physics 2023-12-18 Raphael Skalidis , Paul F. Goldsmith , Philip F. Hopkins , Sam B. Ponnada

The cold neutral medium (CNM) is where neutral atomic hydrogen (HI) is converted into molecular clouds, so the structure and kinematics of the CNM are key drivers of galaxy evolution. Here we provide new constraints on the vertical…

Astrophysics of Galaxies · Physics 2024-09-30 Daniel R. Rybarczyk , Trey V. Wenger , Snezana Stanimirović

CO line emission represents the most accessible and widely used tracer of the molecular interstellar medium. This renders the translation of observed CO intensity into total H2 gas mass critical to understand star formation and the…

Astrophysics of Galaxies · Physics 2015-06-12 Alberto D. Bolatto , Mark Wolfire , Adam K. Leroy

We report a new search for 12CO(1-0) emission in high-velocity clouds (HVCs) performed with the IRAM 30 m telescope. This search was motivated by the recent detection of cold dust emission in the HVCs of Complex C. Despite a spatial…

Astrophysics · Physics 2009-11-13 M. Dessauges-Zavadsky , F. Combes , D. Pfenniger

We observed HCO$^+$ $J=1-0$ and H$^{13}$CO$^+$ $J=1-0$ emission towards the five protoplanetary disks around IM Lup, GM Aur, AS 209, HD 163296, and MWC 480 as part of the MAPS project. HCO$^+$ is detected and mapped at…

We present a study of chemistry toward 294 dense cores in 12 molecular clumps using the data obtained from the ALMA Survey of 70 $\mu \rm m$ dark High-mass clumps in Early Stages (ASHES). We identified 97 protostellar cores and 197…

We present ALMA observations of the dwarf starburst galaxy Henize 2-10 in combination with previous SMA CO observations to probe the molecular environments of natal super star clusters. These observations include the HCO$^+$(1-0), HCN(1-0),…

Galaxy halos appear to be missing a large fraction of their baryons, most probably hiding in the circumgalactic medium (CGM), a diffuse component within the dark matter halo that extends far from the inner regions of the galaxies. A…

We aim to explore the capabilities of dust emission and rays for probing the properties of the interstellar medium in the nearby anti-centre region, using gamma-ray observations with the Fermi Large Area Telescope (LAT), and the thermal…

High Energy Astrophysical Phenomena · Physics 2017-05-10 Q. Remy , I. A. Grenier , D. J. Marshall , J. M. Casandjian

We have investigated the presence of dense gas toward the radio source Cen A by looking at the absorption of the HCO+ and HCN (3-2) lines in front of the bright continuum source with the Submillimeter Array. We detect narrow HCO+ (3-2)…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 Sebastien Muller , Dinh-V-Trung

We use UV measurements of interstellar CO towards nearby stars to calculate the density in the diffuse molecular clouds containing the molecules responsible for the observed absorption. Chemical models and recent calculations of the…

Astrophysics of Galaxies · Physics 2015-06-16 Paul F. Goldsmith

While the CO(1-0) transition is often used to deduce the total molecular hydrogen in galaxies, it is challenging to detect in low metallicity galaxies, in spite of the star formation taking place. In contrast, the [CII] 158 micron line is…